Fuse



June 26, 1928. 1,674,633

, R. E. BOWEN FUSE Filed June '7, 1926 INVENTOR.

BY ggf/G44@ ATTORNEYS Patented June 2.6, 1928.

` UNITED kSTATES BOY E. BOWEN, OF INDIANAPOLIS, INDIANA.

FUSE.

Application led June 7,

The object of my invention is to produce an improved renewable' fuse in which deleterious results from the electrical rupture of the fusible element are prevented by the rapid volatilization and expansion of an element closely associated with the fusible element at or near the rupture point.

The accompanying drawings illustrate my invention. Fig. 1 is an axial section of an embodiment of my invention, and Fig. 2 a plan. I

In thedrawings indicates the main tubular body of insulating material, one end of thebore 1 1 being enlarged, as indicated at 12.

The open ends of body 10 are covered by removable conducting caps 13 and 14 of such form as to coact with the usual standard terminal clips ordinarily provided for a reception of cartridge fuses.

The renewable fuse element comprises two electrical conductors so associated as to be electrically connected by a fusible element so that there will be formed around the rupture point of the fusible element a chamber within which may be retained what may be termed an explosive material.

In the drawing this renewable fuse element F comprises a metal cup15, an insulating cupV 16, a metal cup 17, an insulating wrapper 18, a fusible element 19 soldered at one end to the interior of cup 15, passed through the bottom of the insulating cup 16 and the bottom of cup 17 and soldered tosaid bottom, a small quantity of material 2O which will readil volat-ilize and expand under the action of the heat produced by the electrical rupture of the fusible element 19, a flexible conductor 21, one end of which is secured to the cup 17 anda coil spring 22, one end of which is secured to cup 17. A free end of conductor 21 may be secured to cap 13 by a screw 23 and the free end of spring 22 is secured to cap 13 by screw .24. The material 20 may be any one of a number which will readily suggest themselves, liquid, solid, granular, etc. In practice I have found that a few drops of water are entirely satisfactory.

In order to facilitate renewal cup 15 is provided with a threaded stem 25 which projects through cup 14 and receives a e clamping nut 26.

It will be readily understood that the details of 'construction of the renewable fuse element may be very substantially modified 1926. serial No. 114,162.

from the spirit of my invention. In practice cup 16 and wrapper 18 may be of paper and held in place by 'shellac or other similar material, the binding strength being merely suflicient to retain the parts together and seal the material 20 from loss by leakage or evaporation.

The fusible element 19 may, if desired, be provided in the usual manner, with a welldefined rupture point within the interior of cup 15 in such positionas to be either submerged by the volatilizable material near enough thereto to insure rapid volatilization upon electrical rupture of the fusible element.

In practice it is convenient to have the element F made to slidingly fit the smaller portion of the bore 11.

In use the spring 22 is placed under tension when the parts are brought to the position shown in Fig. 1. .Upon electrical rupture of the fusible element 19 the material 20 is quickly volatiliz'ed and the pressure produced by its expansion ruptures wrapper 18 and blows cups 16 and 17 towards the opposite end of tube 10 into the enlarged portion 12 of the bore, the gases venting through passage 27 in cap 13. Spring 22 is of such length as to retain cup 17, and consequently the attached end of the flexible conductor 21, out of contact with cup 15.

I claim as my invention:

1'. A fuse comprising a hollow insulating body having two separated electrical contact elements, two rupturably associated contact elements forming a hollow unit within said body and electrically associated with the first mentioned contact elements, a fusible element electrically connecting the second two contact elements and within the hollow unit, and a quantity of material associated with the fusible elementwithin the hollow unit and volatilizable under the heat of electrical rupture of t-he fusible element.

2. A fuse comprising a tubular body of insulating material, externally accessible contact caps for said tubular body, a renewable element comprising a terminal cup electrically associable with one of sai contact caps, a contact element rupturably associated with the terminal cup in such manner as to seal said cup, a fusible element within the cup and electrically connecting said cup and contact element, a small quantity of readily volatilizable material within the cup and associated with the fusible'element adjacent its rupture point, a flexible conductor without departing lll ` y. connecting said contact eleinent with the other contact cap, and means for retaining said contact element away from the terminal cup upon electrical rupture of the fusible element.

3. A fuse comprising a tubular body of insulating material, externallyl accessible contact caps therefor,` and a renewable fuse mounted within said main body, said fuse comprising a contact cup, means for electrically associating @the same with one of the contact caps, a second contact cup, an in- '.sulating cup' interposed between the two contact cups, an insulator wrapper rupturably associating 'said cups, a fusible elementa small quantityof material within a contact' cup and encompassing a portion of the fusible element adjacent its rupture point, a flexible conductor and a spring connected to the second contact cup and to the second contact cap. l l

In witnessv whereof, I have hereunto set ny hand at Indianapolis, Indiana,this 4th ay dred and twenty six.

- ROY E. BOWEN.

of June, A. D. one thousand nine hun- 

